The optical control of Linear Optical Trajectory, or LOT, in which the predator keeps its prey moving in a straight line and at a constant speed against the background from his or her perspective, geometrically guarantees interception. Researchers used Ace bandages to mount micro-video cameras onto the heads of two experienced Frisbee-catching dogs.

Romeo, a Springer Spaniel, and Lillie, a Border Collie, ran between two and fourteen meters to catch Frisbees that were launched at varying angles and forces from a distance of nine to nineteen meters from their side. Researchers coded 63 trials and an additional five where the Frisbee was deliberately thrown so it would begin moving in the opposite direction at a greater speed mid-flight. By measuring the trajectory of the Frisbee from the perspective of the moving dog, researchers found that Romeo and Lillie "kept the Frisbee moving in a straight line and at a constant speed against the background scenery, from their perspective."

Their trajectories and use of LOT are very similar to those previously determined to be used by outfielders running to catch fly balls. Even though the paths of baseballs are somewhat predictable, Frisbees can change dramatically. When they were thrown to change direction mid-flight, the dogs maintained their LOT strategies by resetting their parameters to keep the objects in a second straight line. The findings support that "LOT is a generic tracking strategy used not only in humans but by dogs as well."

top photo in honor of Sweet MacIntosh, UD, PT, AD, VAD
"Tosh" April, 1986 - December, 2000.
See his story,

Outfielder - courtesy fotosearch